A POS (Position and Orientation System) sensor is used for acquiring position and attitude information.
A DEM (Digital Elevation Model) is a virtual representation of typography, and can be obtained by means of photogrammetry based on aerial or satellite images. As basic data for orthorectification of digital images, a DEM is a necessary condition for establishing a collinearity equation in photogrammetry.
In recent years, imaging hyper-spectrometer remote sensing technology, with the characteristics of images and spectrum integration, high spatial and spectral resolution and the like, has promoted agricultural remote sensing quantitative development, and has a great potential of applications. However, a satellite remote sensing platform is limited by an orbit, so its over-the-top time is fixed every day, and emergency observation cannot be implemented thereby; and acquisition of image data through piloted aerial remote sensing leads to a high cost and is greatly affected by weather conditions. With the development of drone technology, a novel remote sensing detection technology using a drone as a low-altitude flight platform with an earth observation sensor has developed rapidly, and especially microdrones with the characteristics of good maneuvering flexibility, short operation period, timeliness, low maintenance cost, economy and practicality, etc. are very suitable for mounting minitype imaging hyperspectral equipment to achieve agricultural low-altitude remote sensing observation, and has important research and application value.
A loaded platform of a drone is low in stability and greatly influenced by the airflow speed, and most imaging hyper-spectrometers adopt a linear array sensor push-broom imaging mode, and the linear array spectral position and attitude change all the time during imaging, causing obvious geometric distortion of imaging spectral data. During push-broom imaging of an imaging spectrometer, tens to hundreds of linear array spectral lines are collected per second, and high-precision sensor position and attitude information is required for data geometric correction thereafter. However, due to a relatively small load of a drone, a conventional large high-precision POS system cannot be mounted thereto, the high-precision sensor position and attitude information cannot be collected synchronously during the push-broom imaging, and only low-precision POS data of a sensor mounted simply to the drone is obtained. As a result, geometric distortion of drone-mounted imaging hyperspectral images is difficult to restore, and geometric precise correction has become a bottleneck problem obstructing drone imaging hyperspectral wide application.